The present invention relates to apparatus and methods relating to signs suitable for outdoor use and with changeable message screens. More particularly, the invention relates to signs suitable for roadside and for providing messages viewable and readable at a distance of at least 200 feet.
Prior art changeable message signs with field changeable message screens suitable for roadside use have been cumbersome and expensive due to the conventional methods of constructing the signs. Such signs conventionally utilize a single large sign enclosure for framing and containing a matrix of changeable pixels which form the screen that displays the changeable message. The protection of the pixels, which are typically LED""s and/or mechanically flipped fluorescent panels, as well as associate circuitry, is typically provided by the single large screen enclosure and an integral and unitary screen panel that is transparent or has transparent portions and which covers the entire screen. In the prior art signs the screen enclosure defines and limits the size of the message screen.
The circuitry for driving the pixels in these prior art signs is hardwired in a generally permanent fashion within the sign enclosure for servicing the sign. In portable signs the access door typically includes the screen panel which is swung upwardly and propped open for working on the circuitry and/or pixels.
These prior art signs utilizing LED""s and/or flip panels as the pixels may be constructed of a number of individual circuit boards with the LED""s extending therefrom. The circuit boards are arranged in the desired message screen shape and size within the rigid steel sign enclosure. Typically, the sign controller will either connect independently through multiple conductors from the sign controller to each circuit board and associate LED""s or there will be multiple ribbon cable and associated LED""s or there will be multiple data lines in a daisy chain arrangement to each circuit board.
The sign enclosures are specifically sized for the desired message screen size. A sign controller, either within the screen enclosure or separately enclosed, operates to control the changeable message. Each of the circuit boards is assigned an address and the sign controller will typically utilize ribbon cable and connectors with multiple data conductors to send parallel data to the individual circuit boards for displaying the desired message. See U.S. Pat. No. 4,197,527 to Romney which discloses an outdoor modular sign. As in other prior art signs, Romney discloses the use of extensive cabling and wire harnesses for connecting to and providing control signals to the modules. Moreover, the modules in Romney, as in any other art outdoor signs utilizing modular circuit board arrangement of which the applicants are aware, are enclosed in a sign screen enclosure; thus the sign screen is not expandable. The support and mounting structure for the modules are thus sized for and typically part of such sign enclosures. Moreover any such mounting structure will typically provide only mechanical support for the mounting of the modules. Electrical connections are accomplished separately from the mechanical attachment to the sign enclosure and such electrical connections provide no mechanical support for the module.
As a result of the configurations of conventional prior art exterior changeable message signs, the pixel elements and the circuitry for the pixels are not serviceable from the front of the sign screen. Moreover, typically such prior art signs are not user serviceable and where such service is performed, the sign screen enclosure must be entered or opened thereby exposing all internal circuitry and pixel elements to the weather. This can cause difficulty in field servicing the sign screens particularly during rain or snow showers.
Much, if not the majority of the weight and bulk of traditional outdoor changeable message signs is in the screen enclosure. A breach of the enclosure, such as a crack or hole in the transparent screen panel subjects the entire screen circuitry and pixels to the elements, particularly moisture. Moreover, the size and weight of the screens necessitate heavy machinery, for example a crane, to install such signs.
Moreover, due to the massive weight, principally from the enclosure, dropping the changeable message screens can cause extensive damage to the sign screen or other property. Also, the significant bulk, weight, and rigid metal structure presents a hazard to personnel during the installation of such signs and to motorists who might collide with same.
Moreover, the weight and bulk of traditional outdoor changeable message signs requires a large and expensive support structure to support the enclosure. This of course increases the cost and labor for transportation and erection of such signs.
Moreover, the steel enclosures of the prior art outdoor changeable message signs often require ancillary cooling equipment. This of course, increases the weight, complexity, maintenance issues, and cost of the signs. Moreover, due to the size of the enclosures, effective weatherproofing was difficult. Hermetic sealing of such enclosures is generally impossible.
Thus, the prior art does not disclose an outdoor electronic message sign with characters viewable at a reasonable distance for reading, for example, at least 200 feet away, and which is easily changeable both with respect to the message and with respect to the screen size.
Conventional prior art exterior changeable signs are labor intensive and expensive to manufacture requiring fabrication of a steel screen enclosure, mounting of multiple boards with LED""s or other pixel elements inside the steel enclosure, hardwiring of the components and connection to and enclosure of the sign controller. Typical lead time to manufacture such signs is four to five weeks.
Preferred embodiments of the present invention provides a sign system for creating extremely light weight, reconfigurable, and changeable signs suitable for outdoor use adjacent to roadways. The system, in preferred embodiments can provide adjustable message screen size, electronically changeable messages and adjustable alphanumeric character size of sufficient size to be readable by the average motorist at 150 to 200 feet or more. The system generally comprises a sign controller and a plurality of interchangeable modules each closed or sealed to be weather resistant. Each module of preferred embodiments having a display side with a rectangular screen portion, the screen portion having transparent portions with pixel elements positioned behind said transparent portions and within said module. Each such module has the pixels arranged in a first matrix pattern and sufficient in number to provide alphanumeric characters of and portions of characters of adjustable size of at least 6 inches. Each such module having a bit map memory and being individually addressable with respect to other modules. The modules are arrangeable in a rectangular matrix on a support structure without a sign screen enclosure and with the screen portions of the modules defining a sign screen. The screen size is thus reconfigurable by adding or subtracting display modules. The modules are in communication with the sign controller to receive data for displaying, in conjunction with a plurality of other sign modules, a desired message. The microprocessor allows diagnostic data as to the status of the display module and specifically the pixel elements to be sent to the sign controller.
In a preferred embodiment, each module is comprised of a plastic hermetically sealed enclosure with an open interior and with the module circuitry and pixel elements mounted therein. The modules may be connected to a data output from sign controller by one or more conductors running behind, above, below, or through the display modules. Or communication can be by conductive or optical coupling. The sign controller can thus be remote from the sign screen with minimal numbers of wires extending therebetween.
An object and feature of preferred embodiments is that signs of any desired size can be field constructed by users. Similarly, the size of a message can be changed by the user. The sign is user and field reconfigurable both with respect to screen size and message.
An additional object and feature of preferred embodiments, according to a preferred embodiment, is that each module is extremely light weight and can easily be manually positioned in place by a single person. The weight of conventional changeable message sign with comparable screen size is greater by a magnitude of ten or more. In the embodiment utilizing a track for mounting of display modules the entire sign can be field assembled by a single worker.
An additional object and advantage of preferred embodiments is that each module may be hermetically sealed thereby providing superior weatherproofing over conventional signs.
An additional object and advantage of preferred embodiments is that repairs of a sign constructed from and by said system may be repaired simply by replacing individual modules.
An object and feature of preferred embodiments of the invention is that pursuant to a customer request essentially any size sign can be immediately assembled at the factory from a minimal number of modular sign parts. Thus eliminating traditional sign construction delays of 4-5 weeks. Such a sign can be easily assembled simply by mounting a desired or specified number of display modules on a suitable support. Alternately, the component parts can be shipped in disassembled form for assembly on site by a customer. Moreover, the shipment and transportation of signs according to the invention is easier and less expensive than traditional prior art signs due to their significantly lighter weight and less bulk.
Another object and advantage of preferred embodiments of the invention is that signs according to the invention can utilize many already existing structures, such as standard sheet metal highway signs which would not be usable for conventional prior art changeable message signs due to the weight and bulk of such signs. Moreover, signs according to the invention, can be easily removed from such preexisting structures with minimal or no damage to the structures. Thus a portable changeable message sign according to the invention can be installed in many locations on preexisting structures where if a conventional portable message sign would be utilized same would have to be the trailer version.
Another advantage and feature of preferred embodiments of the invention is that where a pixel is faulty in a particular sign assembly and where the pixel is part of the message, the modules may be easily rearranged, even at the usage site, to a configuration such that the faulty pixel is not part of the displayed message.
Another object and advantage of preferred embodiments of the invention is that the cost to manufacture signs in accordance with the invention are less than traditional changeable highway signs per unit of display area.
Another object and advantage of preferred embodiments of the invention is that the signs may be field assembled in essentially any weather conditions and may be assembled by a single individual minimizing transportation costs.
Another object and advantage of preferred embodiments of the invention is that no separate screen enclosure is utilized or needed. Thus, the size of the sign screen is not limited by the screen enclosure.
Another object and advantage of preferred embodiments of the invention is that the signs present minimal hazard to installers, compared to traditional changeable message signs, due to the instant invention""s light weight. Moreover, less hazard is presented to motorists who collide with such signs.